/Engine/Source/Runtime/SignalProcessing/Public/DSP/Encoders/WavEncoder.h
This should be overridden to, give the properties in InQualityInfo, write a header into OutFileStart. returns true on success, or false on failure.
virtual bool StartFile ( const [FSoundQualityInfo](API\Developer\TargetPlatform\Interfaces\FSoundQualityInfo) & InQualityInfo, [TArray](API\Runtime\Core\Containers\TArray)< uint8 > & OutFileStart )